Blog

Find the 95% confidence interval for the standard deviation of the weight of ten-gallon drums of motor oil:if a sample size of 20 of these drums had a variance of 3.2 ounces.For question 17, give the table value you are going to use in your set up for Chi-squared right. For question 18, give the table value you are going to use in your set up for Chi-squared left.For question 19, give the highest value of your calculated standard deviation of the 95% confidence interval. (Hint/reminder: Chi-squared tables use degrees of freedom)

A student in the research lab is creating a solution of [y] M CrCl[x], how many g should they dissolve in [z] mL to create their solution?

What mass in grams of hydrogen is produced by the reaction of 31.3 g of magnesium with 2.12 g of water?             Mg (s) + 2H2O (l) → Mg(OH)2 (s) + H2 (g)

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H2O (l) → Ca(OH)2 (s) In a particular experiment, a 4.00-g sample of CaO is reacted with excess water and 4.79 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?

Questions 1-5 deal with the z-tables–recall how helpful a sketch of the bell curve can be with regard to finding areas, etc.1. Find the area to the right of z=+1.12.  Express your answer as a decimal.  For example:  0.6255

Note:  Questions 20-25 are drawn from concepts introduced in Ch 6.  You will be using the z-tables for these questions. Remember how helpful it can be to sketch and label a bell curve for each situation.A recent study of teacher salaries in rural areas showed that the average salary was $31,950 a year with a standard deviation of $1400. For question 20, if one teacher is chosen at random, find the probability that this teacher earns more than $32,500 a year. Express your answer as a decimal.  Recall the importance in using a bell curve sketch for this type of question.

Give your answer for the highest value of the 95% confidence interval of the true proportion of women who applied for police training (see question 13). Report your answer to the hundreths place.  Example:  0.28

Dengue fever, an infectious tropical disease carried by mosquitos, has

In the water budget, ________ is the major “receipt” and ________ is the major “expenditure.”

Which of the following is NOT an indicator of current climatic warming?